I've created a custom master page and I'm applying it as the system master page. Everything works fine except workflows. The following screen shot is showing what happens when I start the OOTB approval workflow.
Here is a link to a screen shot (I can't post one yet sorry)
It just loads to this and stops. I'm not seeing any errors in the browser or the ULS. As far as I can tell I've got all the required delegate controls and placeholders. I suspects it's some sort of JS issue but I can't for the life of me work it out. Any ideas folks? Thanks in advance for the assist.
Here is the link to a copy the file.